cw laser recrystallization of 〈100〉 Si on amorphous substrates

Abstract

A polycrystalline silicon film 0.55 μm thick was deposited in a low-pressure CVD reactor on a Si3N4 substrate. Islands of various sizes (2×20 μm up to 20×160 μm) were prepared by standard photolithographic techniques. Laser annealing was then performed under conditions which are known to cause an increase in grain size from ∼500 Å to long narrow crystals of 2×25 μm in a continuous polysilicon film. These same conditions were found to produce single-crystal 〈100〉 material in the (2×20 μm) islands. However, 25×25-μm and 20×160-μm islands remain polycrystalline after the laser scan.